1. **Problem statement:** The perimeter of an isosceles triangle is 32 cm. The ratio of the equal side to the base is 3 : 2. Using Heron's formula, find the area of the triangle.
2. **Step 1: Define variables and express sides in terms of a variable.**
Let the equal sides be $3x$ each and the base be $2x$.
3. **Step 2: Use the perimeter to find $x$.**
The perimeter $P = 3x + 3x + 2x = 8x$.
Given $P = 32$, so:
$$8x = 32$$
$$x = \frac{32}{8} = 4$$
4. **Step 3: Find the lengths of the sides.**
Equal sides: $3x = 3 \times 4 = 12$ cm each.
Base: $2x = 2 \times 4 = 8$ cm.
5. **Step 4: Calculate the semi-perimeter $s$.**
$$s = \frac{12 + 12 + 8}{2} = \frac{32}{2} = 16$$
6. **Step 5: Apply Heron's formula for area $A$.**
Heron's formula:
$$A = \sqrt{s(s - a)(s - b)(s - c)}$$
where $a=12$, $b=12$, $c=8$.
7. **Step 6: Substitute values and simplify.**
$$A = \sqrt{16(16 - 12)(16 - 12)(16 - 8)} = \sqrt{16 \times 4 \times 4 \times 8}$$
8. **Step 7: Calculate the product inside the square root.**
$$16 \times 4 = 64$$
$$64 \times 4 = 256$$
$$256 \times 8 = 2048$$
9. **Step 8: Find the square root.**
$$A = \sqrt{2048} = \sqrt{1024 \times 2} = 32 \sqrt{2}$$
10. **Final answer:**
The area of the isosceles triangle is $32 \sqrt{2}$ cm$^2$.
Isosceles Triangle Area D076Dc
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